The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.

Modeling of Nonlinear and Time-Varying Phenomena in the Guitar

Jyri Pakarinen

Dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the Faculty of Electronics, Communications and Automation for public examination and debate in Auditorium S4 at Helsinki University of Technology (Espoo, Finland) on the 4th of March, 2008, at 12 noon.

Overview in PDF format (ISBN 978-951-22-9243-1)   [639 KB]
Dissertation is also available in print (ISBN 978-951-22-9242-4)


This dissertation studies some of the nonlinear and time-varying phenomena related to the guitar, and suggests new physics-based models for their realistic discrete-time simulation for sound synthesis purposes. More specifically, the tension modulation phenomenon is studied and three new algorithms are introduced for synthesizing it. Energy-related problems are discovered with conventional digital waveguide models when their pitch is varied, and two novel techniques are suggested as a remedy. A new wave digital filter based real-time model is presented for simulating a nonlinear vacuum-tube amplifier stage, found in typical high-quality guitar amplifiers. The first study of the handling noise on wound strings is presented. Using this information together with the time-varying digital waveguide energy compensation techniques mentioned above, a new real-time slide guitar synthesis algorithm is introduced. Also, the generation of flageolet tones on string instruments is discussed and a novel physics-based model for their simulation is presented. In general, the results presented in this dissertation can be used for improving the current physics-based string instrument synthesizers and vacuum-tube amplifier models.

This thesis consists of an overview and of the following 7 publications:

  1. Jyri Pakarinen, Vesa Välimäki, and Matti Karjalainen, 2005, Physics-based methods for modeling nonlinear vibrating strings, Acta Acustica united with Acustica, volume 91, number 2, pages 312-325. © 2005 S. Hirzel Verlag. By permission.
  2. Jyri Pakarinen, Matti Karjalainen, Vesa Välimäki, and Stefan Bilbao, 2005, Energy behavior in time-varying fractional delay filters for physical modeling synthesis of musical instruments, In: Proceedings of the 30th IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2005), Philadelphia, PA, USA, 19-23 March 2005, volume 3, pages 1-4. © 2005 IEEE. By permission.
  3. Vesa Välimäki, Jyri Pakarinen, Cumhur Erkut, and Matti Karjalainen, 2006, Discrete-time modelling of musical instruments, Reports on Progress in Physics, volume 69, number 1, pages 1-78. © 2006 Institute of Physics Publishing. By permission.
  4. Matti Karjalainen and Jyri Pakarinen, 2006, Wave digital simulation of a vacuum-tube amplifier, In: Proceedings of the 31st IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2006), Toulouse, France, 14-19 May 2006, volume 5. © 2006 IEEE. By permission.
  5. J. Pakarinen, H. Penttinen, and B. Bank, 2007, Analysis of handling noises on wound strings, Journal of the Acoustical Society of America, volume 122, number 6, pages EL197-EL202. © 2007 Acoustical Society of America. By permission.
  6. Jyri Pakarinen, Tapio Puputti, and Vesa Välimäki, 2008, Virtual slide guitar, Computer Music Journal, volume 32, number 3, pages 42-54. © 2008 MIT Press. By permission.
  7. Jyri Pakarinen, 2005, Physical modeling of flageolet tones in string instruments, In: Proceedings of the 13th European Signal Processing Conference (EUSIPCO 2005), Antalya, Turkey, 4-8 September 2005, 4 pages. © 2005 European Association for Signal Processing (EURASIP). By permission.

Errata of publications 2 and 7

Keywords: digital signal processing, musical acoustics, model-based sound synthesis, computer music

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© 2008 Helsinki University of Technology

Last update 2011-05-26